Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Are bacteria making you hungry?

20.12.2012
Over the last half decade, it has become increasingly clear that the normal gastrointestinal (GI) bacteria play a variety of very important roles in the biology of human and animals.

Now Vic Norris of the University of Rouen, France, and coauthors propose yet another role for GI bacteria: that they exert some control over their hosts' appetites. Their review was published online ahead of print in the Journal of Bacteriology.

This hypothesis is based in large part on observations of the number of roles bacteria are already known to play in host biology, as well as their relationship to the host system. "Bacteria both recognize and synthesize neuroendocrine hormones," Norris et al. write.

"This has led to the hypothesis that microbes within the gut comprise a community that forms a microbial organ interfacing with the mammalian nervous system that innervates the gastrointestinal tract." (That nervous system innervating the GI tract is called the "enteric nervous system." It contains roughly half a billion neurons, compared with 85 billion neurons in the central nervous system.)

"The gut microbiota respond both to both the nutrients consumed by their hosts and to the state of their hosts as signaled by various hormones," write Norris et al. That communication presumably goes both ways: they also generate compounds that are used for signaling within the human system, "including neurotransmitters such as GABA, amino acids such as tyrosine and tryptophan—which can be converted into the mood-determining molecules, dopamine and serotonin"—and much else, says Norris.

Furthermore, it is becoming increasingly clear that gut bacteria may play a role in diseases such as cancer, metabolic syndrome, and thyroid disease, through their influence on host signaling pathways. They may even influence mood disorders, according to recent, pioneering studies, via actions on dopamine and peptides involved in appetite. The gut bacterium, Campilobacter jejuni, has been implicated in the induction of anxiety in mice, says Norris.

But do the gut flora in fact use their abilities to influence choice of food? The investigators propose a variety of experiments that could help answer this question, including epidemiological studies, and "experiments correlating the presence of particular bacterial metabolites with images of the activity of regions of the brain associated with appetite and pleasure."

Formal publication is scheduled for the February 2013 issue of the Journal of Bacteriology.

(V. Norris, F. Molina, and A.T. Gewirtz, 2012. Hypothesis: bacteria control host appetites. J. Bacteriol. Online ahead of print 9 November 2012.)

The Journal of Bacteriology is a publication of the American Society for Microbiology (ASM). The ASM is the largest single life science society, composed of over 39,000 scientists and health professionals. Its mission is to advance the microbiological sciences as a vehicle for understanding life processes and to apply and communicate this knowledge for the improvement of health and environmental and economic well-being worldwide.

Jim Sliwa | EurekAlert!
Further information:
http://www.asmusa.org

More articles from Life Sciences:

nachricht A room with a view - or how cultural differences matter in room size perception
25.04.2017 | Max-Planck-Institut für biologische Kybernetik

nachricht Studying a catalyst for blood cancers
25.04.2017 | University of Miami Miller School of Medicine

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

Early organic carbon got deep burial in mantle

25.04.2017 | Earth Sciences

A room with a view - or how cultural differences matter in room size perception

25.04.2017 | Life Sciences

Warm winds: New insight into what weakens Antarctic ice shelves

25.04.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>